This invention relates to an electronic calculator capable of easy checking and trustworthy steady calculation, which is provided with a memory means for storing the each inputted calculating item consisted of an operator and a numerical value into an input history storing memory at the ordinary calculator mode, and a means for displaying the stored calculating items for confirmation with the numbers and the total number of the inputted calculating items at the input history display mode, and a means for making displayed calculating items correctable through the substitution, insertion, deletion, etc., and a recalculation means which automatically calls the stored calculating items from the first for recalculation, and, furthermore, a means which, at the ordinary calculation course and after the recalculation, inhibits such an input that is not able to maintain such consistency that operators and numerical values alternately appear, and a means for resuming the calculation by canceling the inhibition, and with which, once calculation is made, the inputted calculating items are confirmable and can be corrected through the minimum number of key operation and the trustworthy results can be easily obtained through automatic recalculation, and, moreover, which can resume the calculation even after suspending the calculation process at any time in order to confirm or correct the inputted data, and enables us trustworthy calculations by making such sequential works of confirming and restarting calculation very easy and steady.
With the prior-art calculators, we must type the same key at least two times in order to find the wrong input.
In addition, if we became anxious for the mistake of our inputted calculating formula, there was no effective way to confirm it at any time on the way during our calculation course and there was no effective way to resume our calculation following next after suspending the calculation task in order to confirm and correct the inputted calculating formula.
The present invention has been made in order to improve these fundamental problems of the prior-art calculators.
In order to improve these problems, this invention memorizes the each pair of numeric value and operator into an input history storing memory, and enables confirmation by displaying the inputted calculating items by the minimum number of key operation at the history display mode, and enables the correction of these inputted items by through the substitution, insertion, deletion, etc., and enables a recalculation means which automatically calls the stored input calculating items from the first for recalculation, and, with these means, once calculation is made, the inputted data become confirmable and can be corrected through the minimum number of key operation and the trustworthy results can be easily obtained through automatic recalculation.
And, furthermore, this invention enables us very trustworthy steady calculation by allowing us very free sequential works of confirming and resuming calculation, with which we can resume the calculation even after suspending the calculation process at any time at will in order to confirm or correct the inputted data, by being provided with the quick looking back means which displays the input history around the inputted last, or a means which displays the input history around the calculating items where the user suspect as his mistake input just after switching to the input history display mode, and a means for proper resuming of the calculation following next just after the confirmation or the correction like that